Perform 2 rounds of SHA256 operation using an initial SHA256 state (C,D,G,H) from a, an initial SHA256 state (A,B,E,F) from b, and a pre-computed sum of the next 2 round message values (unsigned 32-bit integers) and the corresponding round constants from k, and return the updated SHA256 state (A,B,E,F).
Perform 2 rounds of SHA256 operation using an initial SHA256 state (C,D,G,H) from a, an initial SHA256 state (A,B,E,F) from b, and a pre-computed sum of the next 2 round message values (unsigned 32-bit integers) and the corresponding round constants from k, and return the updated SHA256 state (A,B,E,F).